Monochromatic frequency

The motivation for this work is the potential use of chiral (and maybe biisotropic) cylinders as rod antennas and scatterers. Accordingly, Lakhtakia investigated the boundary value problem relevant to the scattering of an incident oblique plane EM wave by an infinitely long homogeneous biisotropic cylinder. This medium is described by the so-called Fedorov representation through the monochromatic frequency-domain constitutive relations ... 

The mathematical evolution of the theory is involved, and struggling with its algebra does little to increase our understanding of photoelectrochemistry. The result for a photocurrent provoked by a light with a monochromatic frequency is... 

Urn is the energy of fhe mfh state and T is inversely proportional to the lifetime of each sfafe. /(f) is fhe temporal shape of the linearly polarized pulse, taken to have forms such a Gaussian or a sech funcfion. fo is the peak field strength and is the monochromatic frequency. 

Luminous intensity h Candela Cd A candela (cd) is the luminous intensity, in a specific direction, from a source that emits a monochromatic frequency of 540 X 1,012 Hz and whose energetic intensity in this specific direction is 1/683 W per steradian... 

RS Raman spectroscopy [210, 211] Scattered monochromatic visible light shows frequency shifts corresponding to vibrational states of surface material Can observe IR-forbidden absorptions low sensitivity... 

Continuous wave (CW) lasers such as Ar and He-Ne are employed in conmionplace Raman spectrometers. However laser sources for Raman spectroscopy now extend from the edge of the vacuum UV to the near infrared. Lasers serve as an energetic source which at the same hme can be highly monochromatic, thus effectively supplying the single excitation frequency, v. The beams have a small diameter which may be... 

Here we consider the response of the system to a monochromatic pump beam at a frequency oi. 

Luminous intensity candela cd Luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540 X 10 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian. 

In the microwave region tunable monochromatic radiation is produced by klystrons, each one being tunable over a relatively small frequency range, or a backward wave oscillator, tunable over a much larger range. Both are electronic devices. Absorption experiments are usually carried out in the gas phase, and mica windows, which transmit in this region, are placed on either end of the absorption cell, which may be several metres in length. Stark... 

Photoelectron spectroscopy involves the ejection of electrons from atoms or molecules following bombardment by monochromatic photons. The ejected electrons are called photoelectrons and were mentioned, in the context of the photoelectric effect, in Section 1.2. The effect was observed originally on surfaces of easily ionizable metals, such as the alkali metals. Bombardment of the surface with photons of tunable frequency does not produce any photoelectrons until the threshold frequency is reached (see Figure 1.2). At this frequency, v, the photon energy is just sufficient to overcome the work function

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Spectroscopic examination of light scattered from a monochromatic probe beam reveals the expected Rayleigh, Mie, and/or Tyndall elastic scattering at unchanged frequency, and other weak frequencies arising from the Raman effect. Both types of scattering have appHcations to analysis. 

When accelerated sufficiently, amplitude-frequency modulation in the absence of dephasing results in signal monochromatization, just like in the case of pure frequency modulation. Before the spectrum collapses, exchange between branches causes their broadening, but after collapse it provides their coalescence into a single line at frequency... 

In the powder diffraction technique, a monochromatic (single-frequency) beam of x-rays is directed at a powdered sample spread on a support, and the diffraction intensity is measured as the detector is moved to different angles (Fig. 1). The pattern obtained is characteristic of the material in the sample, and it can be identified by comparison with a database of patterns. In effect, powder x-ray diffraction takes a fingerprint of the sample. It can also be used to identify the size and shape of the unit cell by measuring the spacing of the lines in the diffraction pattern. The central equation for analyzing the results of a powder diffraction experiment is the Bragg equation... 

FIGURE 1 In the powder diffraction technique, a sample is spread on a flat plate and exposed to a beam of monochromatic (single-frequency) x-rays. The diffraction pattern (inset) is recorded by moving the detector to different angles. 

In the case were the arms are oriented at 45° from the x, y axes, the same equation holds but /i+ has to be replaced hy hx- If the incident light is a monochromatic plane wave of frequency Vopt, this time delay will appear as a phase shift between the aj-beam and y-beam ... 

For studies in molecular physics, several characteristics of ultrafast laser pulses are of crucial importance. A fundamental consequence of the short duration of femtosecond laser pulses is that they are not truly monochromatic. This is usually considered one of the defining characteristics of laser radiation, but it is only true for laser radiation with pulse durations of a nanosecond (0.000 000 001s, or a million femtoseconds) or longer. Because the duration of a femtosecond pulse is so precisely known, the time-energy uncertainty principle of quantum mechanics imposes an inherent imprecision in its frequency, or colour. Femtosecond pulses must also be coherent, that is the peaks of the waves at different frequencies must come into periodic alignment to construct the overall pulse shape and intensity. The result is that femtosecond laser pulses are built from a range of frequencies the shorter the pulse, the greater the number of frequencies that it supports, and vice versa. 

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